Balancer SOR API V3 (#37)

Cargo.toml

@@ -48,7 +48,9 @@ observe = { git = "https://github.com/cowprotocol/services.git", tag = "v2.265.0
 shared = { git = "https://github.com/cowprotocol/services.git", tag = "v2.265.0", package = "shared" }
 dto =  { git = "https://github.com/cowprotocol/services.git", tag = "v2.265.0", package = "solvers-dto" }
 rate-limit =  { git = "https://github.com/cowprotocol/services.git", tag = "v2.265.0", package = "rate-limit" }
+number =  { git = "https://github.com/cowprotocol/services.git", tag = "v2.265.0", package = "number" }
 
 [dev-dependencies]
 glob = "0.3"
+maplit = "1"
 tempfile = "3"

src/domain/solver/dex/mod.rs

@@ -115,7 +115,6 @@ impl Dex {
         order: &Order,
         dex_order: &dex::Order,
         tokens: &auction::Tokens,
-        gas_price: auction::GasPrice,
     ) -> Option<dex::Swap> {
         let dex_err_handler = |err: infra::dex::Error| {
             infra::metrics::solve_error(err.format_variant());
@@ -149,7 +148,7 @@ impl Dex {
         let swap = async {
             let slippage = self.slippage.relative(&dex_order.amount(), tokens);
             self.dex
-                .swap(dex_order, &slippage, tokens, gas_price)
+                .swap(dex_order, &slippage, tokens)
                 .await
                 .map_err(dex_err_handler)
         };
@@ -183,7 +182,7 @@ impl Dex {
     ) -> Option<solution::Solution> {
         let order = order.get();
         let dex_order = self.fills.dex_order(order, tokens)?;
-        let swap = self.try_solve(order, &dex_order, tokens, gas_price).await?;
+        let swap = self.try_solve(order, &dex_order, tokens).await?;
         let sell = tokens.reference_price(&order.sell.token);
         let Some(solution) = swap
             .into_solution(

src/infra/config/dex/balancer/file.rs

@@ -2,6 +2,7 @@ use {
     crate::{
         domain::eth,
         infra::{config::dex::file, contracts, dex},
+        util::serialize,
     },
     ethereum_types::H160,
     serde::Deserialize,
@@ -20,6 +21,15 @@ struct Config {
     /// Optional Balancer V2 Vault contract address. If not specified, the
     /// default Vault contract address will be used.
     vault: Option<H160>,
+
+    /// Chain ID used to automatically determine contract addresses and send to
+    /// the SOR API.
+    #[serde_as(as = "serialize::ChainId")]
+    chain_id: eth::ChainId,
+
+    /// Whether to run `queryBatchSwap` to update the return amount with most
+    /// up-to-date on-chain values.
+    query_batch_swap: Option<bool>,
 }
 
 /// Load the driver configuration from a TOML file.
@@ -29,10 +39,7 @@ struct Config {
 /// This method panics if the config is invalid or on I/O errors.
 pub async fn load(path: &Path) -> super::Config {
     let (base, config) = file::load::<Config>(path).await;
-
-    // Take advantage of the fact that deterministic deployment means that all
-    // CoW Protocol and Balancer Vault contracts have the same address.
-    let contracts = contracts::Contracts::for_chain(eth::ChainId::Mainnet);
+    let contracts = contracts::Contracts::for_chain(config.chain_id);
 
     super::Config {
         sor: dex::balancer::Config {
@@ -43,6 +50,8 @@ pub async fn load(path: &Path) -> super::Config {
                 .unwrap_or(contracts.balancer_vault),
             settlement: base.contracts.settlement,
             block_stream: base.block_stream.clone(),
+            chain_id: config.chain_id,
+            query_batch_swap: config.query_batch_swap.unwrap_or(false),
         },
         base,
     }